Search results for "Clinical imaging"

Molecular in vivo imaging of gastric cancer in a human-murine xenograft model: targeting epidermal growth factor receptor

2012

Background The prognosis of gastric cancer depends on early diagnosis. Targeted therapies against epidermal growth factor receptors (EGFRs) are currently emerging for the treatment of gastric cancer. Objective To specifically visualize gastric cancer by using monoclonal antibodies targeting EGFR1 as molecular probes for in vivo molecular confocal laser endomicroscopy (mCLE) in a human-murine xenograft model. Design Prospective in vivo animal study. Setting Animal laboratory. Interventions Human gastric carcinoma xenografts were examined in 26 nude mice by using mCLE after injection of fluorescently labeled antibodies. Nine mice received low-dose anti-EGFR1 antibodies, 7 mice cetuximab, and …

Heart and Brain in Magnetic Resonance Imaging

2021

Discovery of nuclear magnetic resonance (NMR) in the 1940s of the 20th century led to a tremendous development of techniques used in physics, chemistry, biology and medicine. Magnetic resonance imaging (MRI), which is a medical application of NMR, is nowadays a crucial diagnostic tool for the visualization of soft tissues. In the 80s, when NMR first emerged as a widespread clinical imaging method, it originally was a part of nuclear medicine. Eventually, MRI broke away from nuclear medicine and became a separate imaging technique. Interestingly, nowadays it is possible to superimpose nuclear medicine images with MRI to correlate and interpret information from two different exams on one imag…

2013

Background To monitor viability of implanted genetically engineered and microencapsulated human stem cells (MicroBeads) in the mouse eye, and to study the impact of the beads and/or xenogenic cells on retinal integrity. Methodology/Principal Findings MicroBeads were implanted into the subretinal space of SV126 wild type mice using an ab externo approach. Viability of microencapsulated cells was monitored by noninvasive retinal imaging (Spectralis™ HRA+OCT). Retinal integrity was also assessed with retinal imaging and upon the end of the study by light and electron microscopy. The implanted GFP-marked cells encapsulated in subretinal MicroBeads remained viable over a period of up to 4 months…

Funktionelle Bildgebung der Lunge mit gasförmigem Kontrastmittel: ³Helium-Magnetresonanztomographie

2005

Current imaging methods of the lung concentrate on morphology as well as on the depiction of the pulmonary parenchyma. The need of an advanced and more subtle imaging technology compared to conventional radiography is met by computed topography as the method of choice. Nevertheless, computed tomography yields very limited functional information. This is to be derived from arterial blood gas analysis, spirometry and body plethysmography. These methods, however, lack the scope for regional allocation of any pathology. Magnetic resonance imaging of the lung has been advanced by the use of hyperpolarised (3)Helium as an inhaled gaseous contrast agent. The inhalation of the gas provides function…

Reconstruction of hyperspectral cutaneous data from an artificial neural network-based multispectral imaging system.

2011

International audience; The development of an integrated MultiSpectral Imaging (MSI) system yielding hyperspectral cubes by means of artificial neural networks is described. The MSI system is based on a CCD camera, a rotating wheel bearing a set of seven interference filters, a light source and a computer. The resulting device has been elaborated for in vivo imaging of skin lesions. It provides multispectral images and is coupled with a software reconstructing hyperspectral cubes from multispectral images. Reconstruction is performed by a neural network-based algorithm using heteroassociative memories. The resulting hyperspectral cube provides skin optical reflectance spectral data combined…

Marquage de molécules biologiques par des complexes de radiométaux à base de polyamines macrocycliques

2012

This work conducted at the “Institut de Chimie Moléculaire de l’Université de Bourgogne” carries at first on the synthesis of bifunctional chelating agents suitable for the chelation of trivalent radiometals, including indium-111. The greater part of this work was then dedicated to the grafting of a DOTA derivative bifunctional chelating agent on different antibodies or fragments of monoclonal antibodies: trastuzumab (anti-HER2 treatment of breast cancer), cetuximab (anti EGFR, treatment of many cancers, including colorectal cancer) and abciximab (antiplatelet). Particular attention was paid to the characterization of various immunoconjugates. The critical step of this thesis consisted in t…

Radioactive labeling of defined HPMA-based polymeric structures using [18F]FETos for in vivo imaging by positron emission tomography.

2009

During the last decades polymer-based nanomedicine has turned out to be a promising tool in modern pharmaceutics. The following article describes the synthesis of well-defined random and block copolymers by RAFT polymerization with potential medical application. The polymers have been labeled with the positron-emitting nuclide fluorine-18. The polymeric structures are based on the biocompatible N-(2-hydroxypropyl)-methacrylamide (HPMA). To achieve these structures, functional reactive ester polymers with a molecular weight within the range of 25,000-110,000 g/mol were aminolyzed by 2-hydroxypropylamine and tyramine (3%) to form (18)F-labelable HPMA-polymer precursors. The labeling procedure…

In vivo imaging and quantification of the continuous keratin filament network turnover

2008

Keratin polypeptides are major components of the epithelial cytoskeleton forming a filamentous 3D-network. Like intermediate filament polypeptides of other cell types, keratins make up a stable, but elastic network that is responsible for mechanical stress resilience. At the same time the keratin network is able to change its shape during development, cell division, metastasis and cell migration.

Magnetic separation of encapsulated islet cells labeled with superparamagnetic iron oxide nano particles.

2012

Islet cell transplantation is a promising option for the restoration of normal glucose homeostasis in patients with type 1 diabetes. Because graft volume is a crucial issue in islet transplantations for patients with diabetes, we evaluated a new method for increasing functional tissue yield in xenogeneic grafts of encapsulated islets. Islets were labeled with three different superparamagnetic iron oxide nano particles (SPIONs; dextran-coated SPION, siloxane-coated SPION, and heparin-coated SPION). Magnetic separation was performed to separate encapsulated islets from the empty capsules, and cell viability and function were tested. Islets labeled with 1000 μg Fe/ml dextran-coated SPIONs expe…

PET Imaging of the Impact of Extracellular pH and MAP Kinases on the p-Glycoprotein (Pgp) Activity

2012

The functional activity of p-glycoprotein (Pgp) can be increased in vitro by an extracellular acidosis via activation of MAP kinases (p38, ERK1/2). In order to study these effects in vivo a new (68)Ga-labeled PET tracer was developed which serves as a substrate of the Pgp and therefore indirectly mirrors the Pgp activity. For in vivo studies, experimental tumors were imaged under acidic conditions (inspiratory hypoxia, injection of lactic acid) and during inhibition of MAP kinases in a μ-PET system. In vitro, [(68)Ga]MFL6.MZ showed an accumulation within the cells of about 20% which was increased to 30% by Pgp inhibition. In solid tumors a marked tracer uptake was observed showing spatial h…